Give an alert when empty rate field when item selecting

Give an alert when empty rate field. it should ignore if value is given as 0.00 and greater than zero.

function (record, runtime, search, currentRecord) {
“use strict”;
const ITEM_ID = [“852”];

    /**
   * Validation function to be executed when sublist line is committed.
   *
   * @param {Object} scriptContext
   * @param {Record} scriptContext.currentRecord - Current form record
   * @param {string} scriptContext.sublistId - Sublist name
   *
   * @returns {boolean} Return true if sublist line is valid
   *
   * @since 2015.2
   */
    function validateLine(scriptContext) {
        try {
            if (scriptContext.sublistId != "item") {
               
                let rec = scriptContext.currentRecord;

                let itemId = rec.getCurrentSublistValue({
                    sublistId: "item",
                    fieldId: "item"
                });

                let isItemId = ITEM_ID.includes(itemId);                  

                let rate = rec.getCurrentSublistValue({
                    sublistId: "item",
                    fieldId: "rate"
                });
                    //check the condition whether the rate field selected or not

                if (isItemId == false && !rate.toString().trim()) {                        
                    alert("Please Enter Rate");
                    return false;
                } 
                return true;                  
            }
        } catch (e) {
            console.log("error@validateLine", e);
            return true;
        }
    }
return {
            validateLine: validateLine            
        };

    });